<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <script>
    // 1. 立即执行函数要加
    // (function () { })();
    // (function () { })();
    // 2. 使用数组的时候
    
  </script>
</body>

</html>